Exam #3: Respiratory Physiology Flashcards
What does the brain sense in controlling respiratory drive?
The respiratory centers in the medulla sense the arterial partial pressure of: - O2 - CO2 and - pH
Note that these gases must be DISSOLVED to exert partial pressure & not conjugated
What are the functions of the respiratory system?
- Gas exchange
- Acid-Base Balance
- Phonation
- Defense mechanisms (alveolar macrophages)
- Metabolism & handling of bioactive materails
What structures are included in the upper airway? What is the major function of the upper airway?
Everything from the nose to the vocal cords, including the sinuses
Conditioning of inspired air i.e.
- Warm
- Humidify
- Filter (larger than 10um)
What provides the majority of resistance in the upper airway? What happens when there is a URI?
- The nose provides 50% of the resistance to air coming into the body
- In URI, further increases in nasal resistance lead to mouth breathing when resistance is too high
Describe the branching of the airway from the trachea to the alveoli.
Trachea Main stem bronchi Segmental bronchi Bronchioles Terminal Bronchioles Respiratory Bronchioles Alevolar ducts Alveolar sacs
Where do the alveoli start to appear?
After 16th generation; the terminal bronchioles are the smallest airways without alveoli
(Respiratory bronchioles DO have alveoli)
What is considered the conuducting portion of the airway? What is the respiratory portion of the airway?
The first 16 generations of the lung, including the terminal bronchioles; this is the portion of the airway that brings gas in but does NOT function in respiration
The last 7 generations of the lung that are directly involved in gas exchange are considered the respiratory portion
Which portions of the airway contain cartilage and which do not?
Cartilage= trachea & bronchi Non-cartilage= bronchioles & alveolar ducts
What is the main source of airway resistance in the lower respiratory tract? Why?
Bronchioles
NO cartilage
When does bronchiole constriction occur? How is it treated?
Asthma, COPD
B2 agonist (albuterol)
What are the structural properties of the alveoli?
NO cartilage
NO smooth muscle
Thin membrane that is involved in gas exchange
How is mucous production & clearance balanced?
- Goblet cells & submucosal tracheobronchial glands produce mucous (PNS innervation mostly)
- Ciliated epithelial cells push mucous upward
What is the function of mucous?
Smoother air inflow
Humidifation
What is the effect of PNS stimulation in the lung?
Mucous secretion
What enviornmental factors increase mucous production?
Smoke
Pollutants
What is periciliary fluid? What is the function of perciliary fluid?
Perciliary fluid is the fluid produced by ciliated epithelial cells, which is involved in:
1) Cl- secretion
2) Na+ absorption